Improved reception efficiency through rear lens integration… Expected to be applied to next-generation optical modules
The localization of core optical communication components to cope with the explosion of data has taken another step forward. The Electronics and Telecommunications Research Institute (ETRI) announced that it has developed the first domestic 200Gbps-class photodetector device applicable to AI data centers and 5G/6G communication infrastructure. A photodetector is a component that converts signals transmitted by light into electrical signals and is a key device that determines the reception performance of data centers and communication networks.
This achievement was unveiled at OECC 2025 and was recently published in the international academic journal 'Optics Express'. ETRI explained that by demonstrating the possibility of processing optical signals up to 224 Gbps per channel, it has increased the processing capacity per channel by approximately double compared to 112 Gbps-class photodetectors widely used in data centers.
The core of the technology is a structure that simultaneously increases speed and light reception efficiency. The research team secured a bandwidth of over 70 GHz and a photoresponse of over 0.75 A/W, and applied a method of integrating an indium phosphide (InP) convex lens on the back of a 0.5 mm × 0.4 mm chip. It is a structure that helps simplify packaging by improving alignment convenience and light reception efficiency without the need for a separate light-receiving lens.
This device is expected to be applied first to the receivers of optical transceivers for internal networks in AI data centers. Since multiple optical transceivers are housed inside data center racks, component unit costs and integration efficiency have a significant impact on the overall system cost. ETRI anticipates that the rear lens integration structure will enable cost reduction in the manufacturing process of 800Gbps and 1.6Tbps optical modules.
The significance is also considerable from an industrial perspective. 200Gbps-class photodetector chips are considered a highly challenging field with few developers worldwide. ETRI announced that it implemented the entire process, from design to fabrication, using domestic technology based on its Indium Gallium Arsenide (InGaAs) photodetector technology and experience in compound semiconductor foundry operations. The related technology has been transferred to the domestic company Wooriro, and ETRI plans to continue supporting its commercialization.
The demand for optical components for data centers continues to grow due to the proliferation of AI, cloud computing, OTT, and VR/AR. This development is expected to serve as an opportunity to reduce dependence on imports while expanding the supply capabilities of the domestic optical device and component industry in the next-generation high-speed optical module market.